“When you first get in, you’re going to ask yourself, 'Why did I sign up for this thing?' Your lips will be freezing. Your hands will be cold,” Patrick said, acknowledging the two parts of our bodies not protected by thermal layers, a neoprene dry suit and hood, or a snorkel mask. “But you’ll get past it.”

He was talking about the near-freezing Icelandic water we were about to spend the next 30-to-40 minutes snorkeling through: the Silfra Fissure. And he wasn’t wrong. The second my skin touched the water, my body experienced a freezing shock unlike no other. But, Patrick was also right about getting past it: The frigid temperature quickly took a backseat to the wonder of the most amazing underwater world I’ve ever seen.

The Fissure

From land, the Silfra Fissure doesn't look like much more than a muted gray and brown landscape.
Catherine Shyu

Everyday, snorkelers and scuba divers flock to Iceland’s Silfra Tectonic Fissure, a freshwater rift between the North American and Eurasian continental plates (which drift apart about two centimeters each year); not for the refreshing water (it’s a constant 35-39° Fahrenheit year round) or the marine life (there isn’t any, aside from some algae and neon green “troll hair”), but for the surreal and vibrant subaquatic beauty.

From land, Silfra looks like a run-of-the-mill lake, surrounded by a muted green-and-brown landscape. But that surface appearance belies what lurks beneath: a cobalt blue underwater wonderland.

Silfra’s waters start their journey at the Langjökull glacier, about 31 miles from the fissure, which is within Iceland’s Thingvellir National Park, a UNESCO World Heritage site. The glacial melt travels underground from Langjökull, making its way through naturally filtering lava rock for anywhere from 30 to 100 years before seeping into Thingvellir Lake. By the time it hits the fissure, it’s so clear that you can see nearly 330 feet underwater, and so pure you can drink it on the spot.

The Preparations

Snorkeling Silfra requires a bit more preparation, gear, and guidance than, say, floating through a Hawaiian cove. The fissure is protected by Thingvellir’s National Park laws, which means snorkelers and divers can only go in with a local guide (at a maximum ratio of four divers or eight snorkelers to one guide). We went with the 5 Star PADI dive center, DIVE.IS. When you sign up for a tour, you can opt to drive yourself (which we did, so we could continue on our journey exploring Iceland’s famed Golden Circle afterward) or be picked up from Reykjavik, about an hour drive away.

DIVE.IS provides the heavy-duty gear—a jumpsuit-like “undergarment,” a thick, full-body dry suit (complete with boots), neoprene hood, wet gloves, a snorkel mask, and fins—but you’ll need to properly layer underneath all of that. The company recommends thermal long underwear and two pairs of thick, wool socks.

Because I’m always cold, I showed up in Smartwool leggings and a long-sleeve shirt—underneath fleece leggings and two additional top layers—but our guide, Patrick, told me I’d be too warm and uncomfortable. I was skeptical, but I removed the extras (except my third pair of socks—I’ll admit I kept those on, though they did make the boots a bit tight). After a safety briefing, Patrick and his colleagues helped our group gear up, making sure our dry suits were properly sealed at the wrists and the neck, our hoods were on securely, and we had gloves, fins, and snorkel masks that fit. Once everyone was suited up, our group gathered at the entrance to the fissure and prepared to lower ourselves into the water, one-by-one (with Patrick leading the way).

The Journey

Even though I had seen pictures of Silfra’s underwater beauty, when I first arrived on site, I had my doubts. From my land perspective, this certainly didn’t look like any bright blue waters I had seen before. But when I got closer and looked at the metal steps we’d take to descend into the water, I saw that they were 100 percent visible—that water is clear.

And then I got in. As soon as I looked under the surface, the piercing blue water enveloped me and everything else melted away. The gentle current very slowly moved me through the “Big Crack,” where the North American and Eurasian tectonic plates are the closest (some spots are so narrow, you can almost touch both continents at the same time), and the water is the deepest.

As I floated along in between the jagged plates, I forgot that most people snorkel to see fish. The rocks formations and the color—a dark blue in the center of the crack that gradually gives way to a jewel-tone green on the side—paired with the utter peacefulness (guides are careful to leave enough space between groups, so there’s no crowding) is better than any animal that would swim by. Every direction I looked—including back toward where we entered the water—offered a different, magnificent perspective.

Before I got to the end of the Big Crack, I rolled over onto my back to get perspective on where I was. As I floated there, the juxtaposition of the underwater and above-water environments really hit me. As soon as I took my head out of the water, I saw that same muted green-and-brown landscape. And as soon as I put my face back in, I was transported back to this magical world. It was as if the surface of the water was a wardrobe, and when I passed through it, I emerged in Narnia.

After the Big Crack, we floated into Silfra Hall, where the width increases and the depth decreases, and then through the vast Silfra Cathedral. Admittedly, my fingers—protected only by wet gloves—were freezing (but the rest of me was bone dry and warm). But every time I thought about the cold, I got distracted by my surroundings: I marveled at the neon green “troll hair” dancing on and around the rocks; I took a sip of the fresh glacial water; I turned around and admired the bubbles floating up from the divers in the Big Crack.

The final part of the journey took us into the shallow Silfra Lagoon, where I could see almost 400 feet through the turquoise water to the other end, including the stairs that we’d climb to exit Silfra. I took my time floating over to those stairs; I wanted to make sure I saw everything; absorbed every vibrant color and peaceful feeling before passing back through the “wardrobe” for the last time and leaving this magical world behind. I took one more sip of Silfra water, and climbed out.